Gaseous electric discharge device



Dec. 21, 1937. A. FEHSE ET AL 2,103,068

GASEOUS ELECTRIC DISCHARGE DEVICE Filed Feb."7, 1935 INVENTORS Patented Dec. 21, 1937 UNITED STATES PATENT OFFICE GASEOUS ELECTRIC DISCHARGE DEVICE Adolf Fehse, Berlin, and Martin Reger, Berlin- Charlottenburg, Germany, assignors to General Electric Company, a corporation of New York Application February '1, 1935, Serial No. 5,462

r In Germany February 15, 1934 2 Claims.

The present invention relates to gaseous electrlc discharge de'vices generally and more particularly the invention relates to such devices having thermionic electrodes.

The object of the invention is to increase the life of such gaseous electric discharge devices. Another object of the invention is to accelerate the starting of such devices. A further object of the invention is to provide a long lived, thermionic electrode for gaseous electric discharge devices. Still further objects and advantages attaching to the device and to its use and operation will be apparent to those skilled in the art from the following particular description.

In accordance with these objects the invention comprises a plurality of elements which are electron emitting when heated and which are mounted in adjacent parallel positions in a gaseous electric discharge device.- Said elements are connected in parallel across apair of leads sealed into the container of the device and form a thermionic electrode. During the operation of the device the gaseous electric discharge is supported by that electron emitting element which emits the most electrons. If during the operation of the device the electron emitting element which has supported the discharge becomes a less prolific emitter of electrons than another of said electron emitting elements, due to burning through of the filament or to a loss of electron emitting material, the discharge is then supported by another of said electron emitting elements. The life of the gaseous electric discharge device is thus materially lengthened. All the thermionic elements are electron emitting when heated during the starting period and the gaseous atmosphere in the device is quickly ionized by the heavy electron emission which accelerates the startin of the discharge in the device. e 40 In the drawing accompanying and forming part of this specification an embodiment of the invention is shown, in which Fig. 1 is a side elevational, partly sectional view of one end of a gaseous electric discharge lamp 45 device having electrodes embodying the invention, Fig. 2 is a top, partly sectional viewof Fig. 1, and- 3 is a side elevational view of a gaseous electric discharge lamp device having electrodes 50 ofthe type shown in detail in Figs. 1 and 2.

Like numbers denote like parts in all the figures.

Referring to the drawing the new and novel gaseous electric discharge lamp device comprises 55 an elongated, tubular container I having a gaseous atmosphere therein, such as rare gas, common gas, a mixture of rare and common gases, a metal vapor, or a mixture of gas .and metal vapor, such as 'a mixture of argon and mercury vapor or neon and sodium vapor. Said container I has a thermionic electrode sealed therein at each end thereof. The electrode structure is shown in detail in Figs. 1 and 2 and comprises a pair of current leads 3 sealed into the thickened portion 2 of'the container. I. A flat metal sheet 4 is fastened to the inner end of each of saidleads 3 by slipping the sleeve 5 of the sheet 4 over the .end of said lead 3 and welding, soldering or clamping said sleeve 5 to the end of said lead 3. Said sheets {are parallel and the inner ends 6 thereof are bent outwardly. Said ends 6 are bridged by helically coiled heater filaments I of high melting point material, such as tungsten. and the ends of said filaments l are fastened to the outer sides of the sheets 4 by inserting said ends through loops 8 in said sheets 4 and by welding or soldering said filament ends to said sheets 4 between said loops 8. Said filaments I surround rods 9 of electron emitting material, such as a pulverized, mixed and sintered body of electron emitting material and high melting point material, such as a mixture of alkali ,earth metal.

oxides and high melting point metal, or a mixture of alkali earth metal oxides, or a mixture 01- After this operation is completed the curved I part III of the leads 3 is cut and extension wires II are fastened to the external ends of said leads 3. Said leads 3 are connected across the terminals of a heating current source, such as a battery or a transformer.

Each of the thermionic elements consisting of the filament 'l and the rod 9 are stretched between the metal sheets 4 parallel to each other and are electrically ,connected in parallel. The three thermionic elements of each electrode are heated to an electron emitting temperature when the heating current is applied across the leadsv 3 of said electrode. The heavy stream of electrons emanating from the electrodes quickly ionizes the gas in the container to accelerate thestarting of the gaseous electric discharge between said electrodes. The discharge is supported during the operation of the device by the particular electron emitting element which has the most favorable electron emission which usually means the electron emitting element which is the most prolific emitter of electrons.

The heater current is applied across the electrode leads 3 during the operating period as well as during the starting period of the device, when desired, or, when desired, the heating current is disconnected, either by hand or automatically, after the starting of the device and the heat generated at the discharge supporting element by the discharge during the operation of the device is radiated and conducted to the other electron emitting elements adjacent the discharge supporting element in sufiicient quantity to maintain said other elements at a temperature such that the other of said elements I, 9 is capable of supporting a discharge if the discharge supporting element loses its efficiency for any reason.

While we have shown and described and have pointed out in the annexed claims certain novel features of the invention, it will be understood that various omissions, substitutions and changes in the forms and details of the device illustrated and in its use and operation may be made by those skilled in the art without departing from the broad spirit and scope of the invention, for example, other types of thermionic elements known in the art, such as a metal filament coated or impregnated with electron emitting material, or a Hull cathode, is used in place of the elements I, 9, when desired.

What we claim as new and desire to secure by Letters Patent of the United States is:-

1. A gaseous electric discharge device comprising a container, electrodes sealed therein, a gaseous atmosphere therein, one of said electrodes comprising a plurality of individual thermionic elements mounted in adjacent parallel positions, said thermionic elements being directly connected in parallel between-a common pair of current leads sealed into said container.

2. A gaseous electric discharge device comprising a container, electrodes sealed therein, a gaseous atmosphere therein, one of said electrodes comprising two supporting elements each of which is connected to a current lead sealed into said container, a plurality of individual thermionic elements each of which is fastened to each of said supporting elements, said thermionic elements being mounted in adjacent parallel positions.

ADOLF FEHSE. MARTIN REGER. 

